dt-bindings: dma: Add lpc32xx DMA mux binding

LPC32XX SoCs use pl080 dma controller which have few request signals
multiplexed between peripherals. This binding describes how devices can
use the multiplexed request signals.

Signed-off-by: Piotr Wojtaszczyk <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Rob Herring (Arm) <[email protected]>

Author: pwojtaszczyk-ts

Documentation/devicetree/bindings/dma/nxp,lpc3220-dmamux.yaml

@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/nxp,lpc3220-dmamux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: DMA multiplexer for LPC32XX SoC (DMA request router)
+
+maintainers:
+  - J.M.B. Downing <[email protected]>
+  - Piotr Wojtaszczyk <[email protected]>
+
+allOf:
+  - $ref: dma-router.yaml#
+
+properties:
+  compatible:
+    const: nxp,lpc3220-dmamux
+
+  reg:
+    maxItems: 1
+
+  dma-masters:
+    description: phandle to a dma node compatible with arm,pl080
+    maxItems: 1
+
+  "#dma-cells":
+    const: 3
+    description: |
+      First two cells same as for device pointed in dma-masters.
+      Third cell represents mux value for the request.
+
+required:
+  - compatible
+  - reg
+  - dma-masters
+
+additionalProperties: false
+
+examples:
+  - |
+    dma-router@7c {
+      compatible = "nxp,lpc3220-dmamux";
+      reg = <0x7c 0x8>;
+      dma-masters = <&dma>;
+      #dma-cells = <3>;
+    };
+
+...

MAINTAINERS

@@ -2428,6 +2428,7 @@ N:	lpc18xx
 
 ARM/LPC32XX SOC SUPPORT
 M:	Vladimir Zapolskiy <[email protected]>
+M:	Piotr Wojtaszczyk <[email protected]>
 L:	[email protected] (moderated for non-subscribers)
 S:	Maintained
 T:	git git://github.com/vzapolskiy/linux-lpc32xx.git
@@ -2440,6 +2441,14 @@ F:	drivers/usb/host/ohci-nxp.c
 F:	drivers/watchdog/pnx4008_wdt.c
 N:	lpc32xx
 
+LPC32XX DMAMUX SUPPORT
+M:	J.M.B. Downing <[email protected]>
+M:	Piotr Wojtaszczyk <[email protected]>
+R:	Vladimir Zapolskiy <[email protected]>
+L:	[email protected] (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/dma/nxp,lpc3220-dmamux.yaml
+
 ARM/Marvell Dove/MV78xx0/Orion SOC support
 M:	Andrew Lunn <[email protected]>
 M:	Sebastian Hesselbarth <[email protected]>